She eventually agreed to sign up because she said Western GPS of Tempe, Ariz., told her it could knock the rate down to zero on one of her cards. While it would cost her $995, she'd save in the long run.

Heinrich should have followed her instincts and hung up. She said she never got a lower interest rate as promised in September, and she was unable to reach Western GPS after that. She said she tried calling several times last month, but the number no longer was in service.

That's because Western GPS has temporarily been shut down by federal authorities who are investigating similar complaints. It's one of several cases the Federal Trade Commission has filed recently against companies accused of misleading people about their ability to reduce their credit card interest rates.

"I feel better knowing that I wasn't the only one," Heinrich, of Bethlehem, told me. "I guess I was just ripe for the picking."

The FTC sought an injunction against Western GPS, along with four other companies, in October. It alleges they operated as a "common enterprise" to call people across the country and offer to lower the interest rates on their credit cards.

The companies told people they could "substantially" reduce their interest rates, in some cases to zero percent, and save them a substantial amount of money, but after accepting payment they often "do not deliver on their promises," the agency's complaint contends.

I couldn't reach Western GPS, either, as its number wasn't working. An attorney representing the company in the FTC case did not return my call.

The FTC said in its complaint that often no interest rate reduction was obtained for customers, and in situations when a lower rate was achieved, it "is often not sufficient to produce the promised savings."

In court papers, attorneys for Western GPS and the other companies denied the allegations and said most customers saved thousands of dollars in interest.

"There is nothing sinister about the business structure," attorneys wrote in court papers filed last month.

They said the evidence that Western GPS and the other firms were offering legitimate products to interested customers "is far stronger than the FTC's flimsy proof" that they were engaged in fraud.

According to court papers, customers who agreed to pay for the service would be put on a three-way call with their credit card issuer in an attempt to reduce their interest rate. The companies also would apply for zero percent interest rate credit cards on the customer's behalf, and help them transfer a balance from higher-rate cards. Customers were charged only if the agreed-upon savings were reached.

Heinrich told me that after she talked with Western GPS, she received paperwork in the mail suggesting a new payment schedule, but the rate on her card remained the same and she never got a new card with a lower interest rate. She said she never was on a three-way call with her card issuer.

"They didn't do anything," Heinrich said.

A federal judge in Arizona temporarily has frozen the assets of the accused companies and appointed a temporary receiver to take control of their assets. Attorneys for the companies said in court papers that the freeze is unwarranted and "based primarily on innuendo and conjecture."

I suggested Heinrich call her credit card and dispute the $995 charge from Western GPS. She said she called and was told the charge would be removed.

"They're going to take care of it," she said.

That sounds promising, and is an option for others who have found themselves in the same situation.

I've received a lot of complaints about companies calling people on the Do Not Call list and pitching credit card interest reduction. People want to know what they can do to stop the calls. Frankly, they're hard to stop. The best thing to do is ignore them.

There's no reason to pay someone to try to lower the interest rates on your credit cards. You can call your issuer directly and ask for a lower rate.

If you're never late with your payment and have been a longtime customer, stress that. If the customer service representative won't play ball, ask to speak to a supervisor.

If your credit card issuer won't agree, shop around for a new card with a lower rate. Many cards have zero percent or low rates for an initial period. Be aware that opening a new account can affect your credit rating.

The Watchdog is published Thursdays and Sundays. Contact me by email at watchdog@mcall.com, by phone at 610-841-2364 (ADOG), by fax at 610-820-6693, or by mail at The Morning Call, 101 N. Sixth St., Allentown, PA, 18101. Follow me on Twitter at mcwatchdog and on Facebook at Morning Call Watchdog.